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Gizmo now supports registering against other SIP proxies!

Michael Robertson announced the arrival of Gizmo Project 2.0. The main feature in this release is the ability to register your Gizmo client against Asterisk, but it should work with other SIP proxies as well.

Gizmo Project 2.0 now has support for Asterisk, making it possible to easily configure it to remotely receive and dial calls from from an Asterisk system on any net-connected PC. It’s nothing new to use software to accept Asterisk calls. What IS new is to be able to do it reliably. Oftentimes, Asterisk calls get blocked by routers, NATs and firewalls using other SIP software, so the phone rings but one or both parties can’t hear each other.

How do they do this reliably? It looks pretty simple to me–they proxy everything through the SIPPhone proxies. From a NAT traversal point of view, this is a good thing. Presumably they have already licked NAT traversal between a Gizmo client and the SIPPhone proxy servers. By registering the alternate SIP credentials from the SIPPhone proxy, which is directly on the Internet, they eliminate the potential for NAT traversal issues for the secondary SIP connection. I have some some sniffing and can ve that both the call control the media is proxied through SIPPhone’s servers.

From Asterisk’s point of view, it looks like this:

asterisk*CLI> sip show peer myext

* Name : myext
Secret : <Set>
MD5Secret : <Not set>
Context : international-usa
Subscr.Cont. : <Not set>
Language :
AMA flags : Unknown
CallingPres : Presentation Allowed, Not Screened
Callgroup :
Pickupgroup :
Mailbox : myext@default
VM Extension : asterisk
LastMsgsSent : 2
Call limit : 0
Dynamic : Yes
Callerid : "" <>
Expire : 15370981
Insecure : no
Nat : Always
ACL : No
CanReinvite : No
PromiscRedir : No
User=Phone : No
Trust RPID : No
Send RPID : No
DTMFmode : rfc2833
LastMsg : 0
ToHost :
Addr->IP : Port 5060
Defaddr->IP : Port 5060
Def. Username: 1747xxxxxxx
SIP Options : (none)
Codecs : 0x50e (gsm|ulaw|alaw|g729|ilbc)
Codec Order : (ilbc,ulaw,alaw,gsm,g729)
Status : Unmonitored
Useragent : MacGizmo (Gizmo-s2n1)/1.5
Reg. Contact : sip:[email protected]:5060

I have to give Michael Robertson and the rest of the crew over at Gizmo major kudos, this is a great feature!

#Cybersecurity Evangelist, Podcaster, #noagenda Producer, Frequenter of shiny metal tubes, Expressor of personal opinions, and of course, a coffee achiever.